Translational and rotational dynamics of water in mesoporous silica materials: MCM-41-S and MCM-48-S
نویسندگان
چکیده
We investigated the translational and rotational dynamics of water molecules in mesoporous silica materials MCM-41-S and MCM-48-S using the incoherent quasielastic neutron scattering technique. The range of wave vector transfers Q covered in the measurements was from 0.27 to 1.93 Å broad enough to detect both the translational and rotational contributions to the scattering. We used the relaxing-cage models for both translational and rotational motions which we developed earlier, to analyze the QENS spectra and investigated water dynamics in a supercooled range from 250 to 280 K. The results show a marked slowing down of both the translational and rotational relaxation times, and an increasing effect of confinement on the translational motion, as the temperature is lowered. © 2003 American Institute of Physics. @DOI: 10.1063/1.1584653#
منابع مشابه
The Effect of Processing Conditions on the Mechanical Properties of Polypropylene/Mesoporous Silica-Hydroxyapatite Hybrid Nanocomposites
This work focused on the influence of processing conditions on the mechanical properties of polypropylene (PP) and PP/mesoporous silica-hydroxyapatite (PP/MCM-41-HA) hybrid nanocomposites. The mechanical properties of PP were enhanced by adding MCM-41-HA nanoparticles. Neat PP and hybrid nanocomposites based on PP, containing maleic anhydride-grafted polypropylene (PP-g-MA) and MCM-41-HA, were ...
متن کاملAntibacterial Activity of Mesoporous Silica Nanofibers
In this research, the fabrication of MCM-41 mesoporous material nanofibers by an electrospinning technique was performed. The MCM-41 nanofibers (MCM-41 NFs) as a novel host on the incorporation of silver has been studied in [Ag(NH3)2]NO3 precursor solution through the heat-treatment process. The formation of silve...
متن کاملApplication of Spherical Mesoporous Silica MCM-41 for Adsorption of Dibenzothiophene (A Sulfur Containing Compound) from Model Oil
Spherical mesoporous silica MCM-41 was synthesized for adsorptive removal of sulfur compounds from fossil fuels using 1mM solution of dibenzothiophene (DBT) in dodecane as model oil. The prepared silica adsorbent has been characterized by nitrogen adsorption-desorption analysis as well as Small Angle X-ray Scattering (SAXS), and transmission and Scanning Electron Microscopy (SEM) methods. R...
متن کاملAsymmetric Synthesis of Modafinil and its Derivatives by using the Functionalized Silica-based Mesoporous MCM-41
Modafinil [2-[(diphenylmethyl)sulfinyl]acetamide] is used clinically in the treatment of narcolepsy and sleeping disorders. The synthesis of modafinil, begins with the reaction of benzhydrol and thioglycolic acid in trifluoroacetic acid to afford benzhydrylsulfinyl acetic acid. The reaction of acid with thionyl chloride in benzene followed by treatment with ammonium hydroxide gave acetamide...
متن کاملPreparation, characterization and determination of photocatalytic activity of MCM-41/ZnO and MCM-48/ZnO nanocomposites
The direct and indirect methods in solvent media and grinding method in a solvent-free media were used to prepare the MCM-41/ZnO and MCM-48/ZnO photocatalysts. The X-ray diffraction (XRD) patterns showed that zinc oxide nanoparticles were put into MCM-41 and MCM-48 substrates and there were ZnO crystallites as secondary phase in the extra framework of mesoporous materials. The decrease of surfa...
متن کامل